CO 2 and its implications

[LRAC]

Ok people i'm an old fashioned engineer you know the guy who's only worked on copper installations and standard refrigerants. Not that i really want to do CO2 but the market is moving towards this and i know jack all.

Some questions,

If CO2 is natural element in the atmosphere what happens when we start venting excess amounts of CO2 or is CO2 extracted from the air and we would not be adding any extra just putting it back.

Does CO2 piework require welding in steel pipe rather than copper and if so will we have to be Lloyds registered welders.

Are CO2 systems comparible to todays standard systems in refrigerant cycles of compression and evaporation.

What sort of pressures are we talking about, are they higher than R410 for example.

As you can see i know jack crap, any basic information that would help me understand this technology would be gratefully appreciated.

Regards
Lrac

[NoNickName]

A standstill liquid CO2 at 30°C will reach 73 bars. Go figure.

[Brian_UK]

A standstill liquid CO2 at 30°C will reach 73 bars. Go figure.

Oh sh*t !!

Our PPE kit will soon include bomb disposal suits.

[NoNickName]

Uh? I don't get it.

[LRAC]

Oh sh*t !!

Our PPE kit will soon include bomb disposal suits.

PPE = Personel protective equipment.

[Brian_UK]

Sorry NNN, forgot the international flavour on here.

Thanks for correcting me LRAC.

[Andy]

Ok people i'm an old fashioned engineer you know the guy who's only worked on copper installations and standard refrigerants. Not that i really want to do CO2 but the market is moving towards this and i know jack all.

Some questions,

If CO2 is natural element in the atmosphere what happens when we start venting excess amounts of CO2 or is CO2 extracted from the air and we would not be adding any extra just putting it back.

Does CO2 piework require welding in steel pipe rather than copper and if so will we have to be Lloyds registered welders.

Are CO2 systems comparible to todays standard systems in refrigerant cycles of compression and evaporation.

What sort of pressures are we talking about, are they higher than R410 for example.

As you can see i know jack crap, any basic information that would help me understand this technology would be gratefully appreciated.

Regards
Lrac

Hi LRAC

With the correct wall thickness copper can be used, but it will be a special. Most people in the UK considering R744 are going the copper way. But with the introduction of Transcritcal systems the pressures will rise, maybe it is time to consider steel or as Star uses in some instances stainless stell pipe.
All pipe being welded and used on refrigeration systems should be by welders qualified to local codes (as stated by PED).
Copper pipe is brazed, BRA standards are appropiate.

On purging you can blow it off provided you don't gas all around you. Purge with R744 gas to another part o the system, then with nitrogen to air, remeber if you blow off liquid to air it will go to a solid in the pipes (co2 ice).

Hope this helps.

Kind Regards Andy

[Dan]

Andy, do you see large transcritical processes being the wave of the future? I cannot. I can see controllable central plants of any sort that use a secondary refrigerant, but I think transcritical systems will be limited to small, controllable installations such as self-contained or centralized applications that use a secondary refrigerant. What are your thoughts?

[Andy]

Andy, do you see large transcritical processes being the wave of the future? I cannot. I can see controllable central plants of any sort that use a secondary refrigerant, but I think transcritical systems will be limited to small, controllable installations such as self-contained or centralized applications that use a secondary refrigerant. What are your thoughts?

Yes Transcritical is difficult to work with, requiring an engineer that is switched on.

In the short term at least chillers will be employed, we may never see central packs used with R744. We could install and commission a large scale transcritcal, but the service guys could not yet cope with it, they would need to be trained gradually, maybe on packaged chillers first

Kind Regards Andy

[taz24]

but the service guys could not yet cope with it, they would need to be trained gradually, maybe on packaged chillers first

Kind Regards Andy

Hi Andy

I remember in another post you mentioned how you take a fridge engineer and then only after about 3 years extra training, they are capable of doing the work.
Do you feel as though the training given to engineers is not up to standard? or is it just a mater of being trained on the type of equipment you work with?
I'm asking because I have experienced training at the sharp end and personaly belive if there were better ways of training I would be intrested to hear.
In my oppinion a lot of training organisations train people to pass exams. I personaly would rather see some one with no formal quals and all the experience in the world.
Do you feel as though training agencies are failing the industry?

Cheers taz.

[taz24]

Do you feel as though training agencies are failing the industry?

Cheers taz.


Maybe i'll start anoth thread on training and what people expect.

taz.

[Andy]

Do you feel as though training agencies are failing the industry?

Cheers taz.


Maybe i'll start anoth thread on training and what people expect.

taz.

No

training of this sort is more a mentoring process. I personally think all classroom training is only a last resort
I train my engineers on site, spending time with the senior engineers on site, then making sure this knowledge is passed on down to more junior engineers.

We do carry out class room training, but only as an introduction to new products

The old apprentiship system with city and guilds qualifications was a good system. The NVQ system should be good, but leaves a lot of room for varience in training.

If you want good training for engineers do it on the job

Kind Regards Andy

[US Iceman]

Do you feel as though the training given to engineers is not up to standard?

What's the standard? The purpose of training schools is to provide a background in the basics of refrigeration, safety, and hopefully some common sense.

This should be considered the absolute minimum. The "on the job" training Andy is talking about is right on. It usually takes a good person at least 2-3 years before they start to get comfortable with refrigeration.

Someone who has not had a good apprenticeship (aka mentoring as Andy said) without any formal training has in all likelehood been exposed to some questionable methods.

Years of experience under a senior refrigeration person is a good thing, but the training aspect should not be minimized.

Then add in some specialized areas, like chillers or supermarkets and you have the makings of a good refrigeration person.

The schools only have so much time available to get the subject matter transferred to the student. The job training is where they really start to learn.

Good refrigeration people take at least 10 years to hatch fully.

[taz24]

Someone who has not had a good apprenticeship (aka mentoring as Andy said) without any formal training has in all likelehood been exposed to some questionable methods.


Good refrigeration people take at least 10 years to hatch fully.

i agree with you and Andy but unfortunatly for some trainees out there the quality of the training is questionable.

One example was one so called engineer I met once in a trade wholesalers did not actualy know what superheat was. I was asstounded and thought he was winding me up. Unfortunatly it was true he had gone through all his so called traing and did not know what superheat was.

Cheers taz.

An extream example maybe and all trades have cowboys out there.
That is why I feel training organasations should give the industry what it wants. Not necessarily the exam board.

[US Iceman]

Don't take me wrong there are some very good teachers out there. Unfortunately, there also some bad ones.

The best ones are people who have worked in the trade for a long time. Others, who didn't like getting dirty or the hours end up teaching.

As the old saying goes; Those that can, do. Those that can't, teach.

Teaching and instruction are honarable professions, but no one should be allowed to teach if they have not spent some time in the industry. The people who have already "walked the walk" make the best instructors.

I'm probably going to take some heat for this, but it's all pertinent to the discussion.

[taz24]

I'm probably going to take some heat for this, but it's all pertinent to the discussion.

I don't think you should take any stick.
I agree with you. I think that tutors should be experienced in the busness before they teach.

Cheers taz.

[Kevin Yeo]

Linde guys have the expertise in CO2 direct expansion Cascade system with ***** system and they have commissioned several projects using central pack.

[Frostman]

Linde guys have the expertise in CO2 direct expansion Cascade system with ***** system and they have commissioned several projects using central pack.

Kevin,

Do you know what kind of compressor, TXV and condenser they are using?

[Quality]

Training companies like many others have to operate and make a profit from the training they provide whichin most situation takes over from the quality training / educating what people need. I agree entirely with your self that many training companies are teaching people to pass the exam at the end, but that has a lot to do with how much the training cost and how much people will pay. The profit margin that is left at the end of the day is the key problem here and that is because the goverment don`t provide any were near the funding that they should. Experience goes a long way, a very long way but I personaly think that experience can only be expresed or exercise if given the chance, where experience and qualifications normaly provide that chance.